1. Field of the Invention
The invention relates to portable computers, and more specifically to handheld computer systems capable of sharing data with desktop and network computer systems.
2. Description of the Related Art
Personal computers are becoming smaller and smaller. Originally personal computers were large items best suited for floor standing or desktop use. Eventually they became smaller so that desktop use became the standard. As time progressed, the units became smaller so that they became transportable in packages now referred to as "luggables". Time proceeded and computer systems became smaller, approaching laptop and, ultimately, notebook sizes. As the portability of the personal computers increased, so did the desire to use them remotely. However, in most cases notebook computers were effectively just small versions of full function desktop computers and so were relatively expensive. Further, they were also relatively heavy. This limited their usefulness as they were quite complex, relatively large and relatively expensive.
Noticing this problem, certain palmtop or handheld units were developed. Often these units were very limited function, i.e. personal organizers and the like. One relatively common drawback was that these units were not compatible with the programs operated on the larger desktop and notebook computers but had proprietary operating systems and programs. This greatly limited their usefulness in that they were effectively stand-alone devices and could not readily transfer data with other stations. Some units were also developed which did include certain common functionality, but they were generally keyboard based and the use of very tiny keyboards made them relatively unpopular. Additionally, they had only minimal features and file transfer was relatively difficult.
One trend which developed after notebook computers had been around for a period of time was a variation referred to as notepad or touchpad computers. These computers were essentially notebook computers with the keyboard removed and a digitizer applied to the display so that a pen or other pointing device could be utilized as an input device. This freed up one aspect of the computer design, mainly the requirement for a keyboard of certain given dimensions. But tradeoffs occurred. One was the relative complexity of handwriting analysis and capture and the slow speed for data entry. Therefore these units could not readily replace conventional notebook computers in many applications but were well suited and adapted for certain environments. Often these environments utilized specialized hardware or operating programs, such as for inventory control and so on, where simple check-offs could be utilized or just limited input functions were required. This limited their usage again to the particular application, so that widespread use did not develop. Additionally, most of the original notepad units were based directly on notebook computers and as such were the sizes of notebook computers, that is approximately 81/2.times.11 inches and one inch thick, weighing 5 to 6 pounds. This was a drawback in that the units were then quite heavy, too heavy to carry for extended periods and were not readily convenient. By the use of particular driver software, it was possible to utilize many of the common personal computer programs, but performance was dramatically reduced because of the complexity of the operating interface and the necessary translations.
Further, as computers reached notebook and notepad sizes, it became common for a user to own two computers, one a desktop system to be used as a main system, often attached to a local area network, and a notebook computer for traveling. This resulted in the capability to use the standard desktop programs, but also some portability was present. A major problem developed in synchronization of the data between the two computers. For instance, certain data such as calendar information and so on would generally be kept on the desktop computer but it would be convenient and desirable to transfer this information to the notebook computer for travelling purposes. However, if the person was travelling and information was entered on the desktop computer or network file server while the user was gone, or if the user entered information on the local version of the data files in the notepad, then the information contained in the desktop computer and in the notebook computer were out of synchronization and major problems could develop. Therefore this synchronization problem also limited applications and the use of two computers, one a desktop and one a notebook, by individuals because the problem was difficult to resolve. Further, if resolutions were possible, they were generally very time consuming and tedious and therefore reduced the effectiveness of the systems or they required relatively detailed system knowledge by the user. One solution was to have the file that physically resided with the user be the master, but then no changes could be made to the other system without danger of being lost. So while dual computer environments existed and were used, they did not become widespread.
Therefore it would be desirable to have a small handheld computer system capable of operating certain personal information management type software such as calendars, telephone directories, and scheduling, as well as simplified versions of applications software, and sharing files with a desktop computer, with all of the files utilized by all of the programs being automatically synchronized by the two computer systems at various times to alleviate the synchronization difficulties.